jon karl says he follows her closely on the campaign trail and no one works harder or more vigorously out there. so far, so good. >>> other news now, the postmaster general is pushing now to cut back mail delivery to just five days a week. he says the post offffe lost $8 billion last year and is on track for a similar loss this year. that's because mail volume is down mostly because of people using the internet for letters and to pay their bills. >>> it is a bittersweet morning for nasa astronauts and crew members as the final shuttle mission comes to an end. it's the end of the historic shuttle program that dates back to the 1980s. while the crew says gogo-bye to the shuttle, many nasa employees ll be saying good-bye to their jobs. >> reporter: on their last full day aboard the space shuttle "atlantis" the crew practiced landings on a computer laptop, peered out the windows and read poetry. the men on the ground who will lead "atlantis" back through the landing said thursday morning would be tough. >> i don't think you'd be human if you didn't feel something. every time you feel some